Aluminum rear knuckles

Suspension, brake, and hydraulic/electric steering discussion.
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kevink
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Aluminum rear knuckles

Post by kevink »

Does anyone have a part number or know what year car would have aluminum knuckles that fit our cars? The Camaro knuckle must be close, but I have not heard of anyone who has actually tried them on a PPV. Do any years of the SS have aluminum knuckles? Do the 2014 and up Caprices have aluminum knuckles? I just read that somewhere, but I would like to confirm it.
2011 9C3: 11.48 @118.
Navy Lifer
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Re: Aluminum rear knuckles

Post by Navy Lifer »

Based on a parts lookup, the rear knuckles for sedans (Holden/Australian built) are common, all the way from 08 G8 to 17 PPV/SS (this is RH side)--all are steel, I believe.
https://www.gmpartsdirect.com/oem-parts ... xleA%3D%3D" onclick="window.open(this.href);return false;

Camaro parts may or may not work--I've seen at least one Forum thread (I believe in a G8 Forum) that describes what is involved in conversion to Camaro Zeta suspension. Park brake sizing for Camaro is different--not sure what else is different.

Front knuckles, although not part of your inquiry, are different between models, years, and material changed for 2014 to aluminum for both SS (VF) & PPV (WN)--all 2014 to 2017 SS & PPV use the same parts.

The top of the (front) knuckle where it is secured in the strut clevis for VF/WN was increased in width to 34mm, where the original cast iron knuckle (G8 & 11-13 PPV) was 1" (25.4mm). This also means that PPV front struts changed accordingly to work with the wider casting--now aluminum--and are unique to 2014-2017 model years. The change in material probably explains why the material thickness was increased.

There has also been a migration over the years of Zeta sedans to aluminum upper control arms, in the rear, at least, and other components changed from cast steel to aluminum in the front suspension, in the transition from VE/WM to VF/WN.
s/c'd cav
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Re: Aluminum rear knuckles

Post by s/c'd cav »

i think with the VF they changed alot in the rear suspension parts , the knuckles should be aluminum , along with the upper control arm

id have to crawl under my 14ppv and check out what parts it has , my guess is they would have changed with the VF's

SS rear

http://www.gminsidenews.com/forums/gall ... 154061.jpg" onclick="window.open(this.href);return false;

SS front

https://salvageautosales.com.au/wp-cont ... G_1671.jpg" onclick="window.open(this.href);return false;
xcidmigs
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Re: Aluminum rear knuckles

Post by xcidmigs »

Whats the point of the original inquiry Kev? weight reduction or something to do with fat rear ballon tires?

Are the later style alum arms a direct swap on the early PPV model? I keep wondering about that upper bushing but the though of dropping the cradle just for that is putting me off
Navy Lifer
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Re: Aluminum rear knuckles

Post by Navy Lifer »

I'm guessing that there may be some difference(s) in the bushings that are used in different rear knuckles--some Camaros and possibly sedans use a spherical bearing rather than a bushing, but the bearings may not be a service item--only way to get the bearing is to get the right knuckle. Still unsure about knuckle material for the rear. Really not sure if SS sedan (VF) uses iron or aluminum rear knuckles, but the parts info suggests iron.

I'm sure that rear upper control arms on (my) 2011 PPV are steel, but there may have been a late production transition to aluminum--gotta check with the dealer. G8 was also steel. The 2012 PPV got aluminum rear upper control arms, and that may have been when the change from steel to aluminum took place....again, will check dealer for the full story.
fuzzkill
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Re: Aluminum rear knuckles

Post by fuzzkill »

My rear uppers on my 13 are aluminum. I was going to replace them but it turns out the noise I heard was a bolt not torqued correctly on the spherical bushing.

When I looked up replacements, some aftermarket arms were steel, some were aluminum.
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kevink
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Re: Aluminum rear knuckles

Post by kevink »

Thanks for all the info so far. Someone on one of the G8 sites said that the SS aluminum upper arms are a direct bolt on for G8s, so they should be a direct bolt on for early PPVs, too. You will need the SS upper arm to knuckle bolt, though, which is longer because the aluminum is thicker than the steel. Steel uppers are 16.5 lbs each and aluminum are 8.8 lbs each for a total weight savings of 15.4 lbs.

The part numbers are the same for PPV and SS uppers (92294159 and 92294160) for all years, which seems odd because the early PPVs have steel uppers. Not sure what to make of that.
2011 9C3: 11.48 @118.
Navy Lifer
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Re: Aluminum rear knuckles

Post by Navy Lifer »

I'm thinking that GM/Holden made a decision to go aluminum, and rather than continue to support the steel arms, to reduce inventory they just made aluminum the default replacement for the earlier steel parts.
xcidmigs
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Re: Aluminum rear knuckles

Post by xcidmigs »

Seems like we got off topic there, KevinK what was the original plan about the knuckles?
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